Negative stimuli get processed by the amygdala; positive or
neutral memories gets processed by the hippocampus. Sleep
deprivation hits the hippocampus harder than the
amygdala. The result is that sleep-deprived people
fail to recall pleasant memories, yet recall gloomy memories just
fine. In one experiment by Walker, sleep-deprived college
students tried to memorize a list of words. They could remember
81% of the words with a negative connotation, like “cancer.” But
they could remember only 31% of the words with a positive or
neutral connotation, like “sunshine” or “basket.”

Take an A student used to scoring in the top 10 percent
of virtually anything she does. One study showed that if she gets
just under seven hours of sleep on weekdays, and about 40 minutes
more on weekends, she will begin to score in the bottom 9 percent
of non-sleep-deprived individuals.

Yes, some people don’t need much sleep but they’re exceedingly rare. Out of 100 people who think
they can go without much sleep, only five really can.

“…those who exercised reported a better quality of sleep than
those who remained sedentary.”

2) Keep it cold:

“One study by researchers in Lille, a city in northeastern
France, found that subjects fell asleep faster and had a better
overall quality of sleep following behaviors that cooled the
body, such as taking a cold shower right before bed. The best
predictor of quality sleep was maintaining a room temperature in
a narrow band between 60 and 66 degrees Fahrenheit (or 16 to 19
degrees Celsius).”

3) Avoid light before bed, and that includes TV’s and
computers:

“…bright lights— including the blue-and-white light that
comes from a computer monitor or a television screen— can deceive
the brain, which registers it as daylight. Lying in bed watching
a movie on an iPad may be relaxing, but the constant bright light
from the screen can make it more difficult for some people to
fall asleep afterward.”

4) Avoid coffee or alcohol at night:

“It is obviously not a good idea to drink coffee in the
evening if it keeps you up at night. Nor is drinking alcohol
before bedtime a smart move. Alcohol may help speed the onset of
sleep, but it begins to take its toll during the second half of
the night. As the body breaks down the liquid, the alcohol in the
bloodstream often leads to an increase in the number of times a
person briefly wakes up.”

Also:

5) Mattress quality doesn’t matter. The only factor that
was relevant with regard to beds was when traveling, people sleep
best on a mattress similar to the one they have at home.